MicroPython Forum (Archive)

pythoncoder wrote: ↑

Sun Jan 16, 2022 5:11 pm

This was my guess as to the cause of the fault. It proved incorrect. Hard I2C can be fixed with this patch.

Very well.
When I have a Pi again I will compile and test the patch.

Except there won't be one for hardware I2C, because the BNO055 IMU requires clock stretching, something the Pico's hardware I2C doesn't support Where did you get this assumption from? - nothing is really written about it on the data sheet. https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet....

pythoncoder wrote: ↑

Fri Jan 14, 2022 2:14 pm

I thought I'd described the solution........

I apologize for my incorrect phrasing. I meant a solution regarding Hard I2C.

I am very interested in whether a solution will be found there!

Before sounding off on GitHub I'd like to make sure we've got our facts straight ;) Yeah well, maybe I'm biased now. Pi Pico with Micropython has given me a lot of migraines over the past few months. :? I am still very excited about your tests. PS: Another question would be: Why does circuit python...

pythoncoder wrote: ↑

Tue Jan 11, 2022 11:18 am

OK, I've now run the test script and can confirm there is a problem, but only on the Pico ........

Thank you for confirming this error.
For several months now I have had the feeling that without the official submission of this dire bug in Github, there will be no real answers and solutions.

Further information: With this test code (fivdi) I can read out the BNO005 with the PiPico and Micropython also with 400000: from machine import Pin, I2C import time # Power-on-reset time for the BNO055 is 650 ms. Give it time to start. time.sleep(1) i2c = I2C(0, scl=Pin(5), sda=Pin(4), freq=400000)...

In addition, the protocol looks perfect, whether it is 4000Hz or 400kHz.
Only that the Pico freezes over 4000Hz for between 2 seconds and 2 minutes.

This doesn't accord with my experience. My bno055 test script runs at 400KHz on Pyboards, and at the default speed for soft I2C on ESP8266 (nominally 400KHz but I haven't actually measured it). We're talking about a PiPico, your library and micropython. It cannot be due to my hardware, because: The...

You have to set the frequency to 4000 then it works properly That is a clear indication that the external pull up resistors are missing, or/and the wires are too long. The internal pull up resistors are 30-40kOhm. Well, first of all: The breakout board built the resistors internally on the board. E...